AirGreen intervention in a condo: diagnosis and repair of a PTAC system
At AirGreen , we often receive calls regarding PTAC (Packaged Terminal Air Conditioner) units installed in condos or apartment buildings. These compact units, built directly into the wall under a window, are popular for their ability to provide heating and cooling in an all-in-one format.
Recently, our team was dispatched to Outremont , Montreal, for a Friedrich PTAC air conditioner with a partial air conditioning failure . The customer had noticed that the blown air was no longer cold, even when the thermostat was set to a minimum temperature.
Initial assessment: identifying the problem
On site, our technician immediately noticed that the Friedrich PTAC compressor was no longer starting, although the interior fan was still operating normally. This type of symptom generally indicates an electrical problem , a faulty control board or a poorly calibrated temperature sensor .
The unit was installed under a large window, with direct access to the outside, typical of PTAC installations in residential buildings. A careful visual inspection revealed some signs of wear:
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A buildup of dust on the condenser coils ,
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A slightly damaged wire near the control module,
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And stagnant condensate , suggesting a slight blockage of the drain.
In-depth diagnosis: AirGreen methodology
Our HVAC specialists conducted a series of structured tests to identify the exact cause of the breakdown. Here are the diagnostic steps:
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Checking the supply voltage – to confirm that the unit was receiving its 240 volts.
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Compressor Test – Measure resistance and continuity to rule out an internal problem.
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Inspection of the electronic control board – looking for signs of corrosion or burnt components.
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Reading temperature sensors – validation of the values returned by the probes to the control panel.
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Starter relay test – often a problem on older PTAC units.
The final diagnosis: Main control board damaged by moisture , preventing the compressor from receiving the start signal. A common cause in installations near exterior openings where condensation builds up over time.
Repair and recommissioning
After customer approval, we proceeded to completely replace the Friedrich electronic board with a certified original part. This replacement was followed by several crucial steps:
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Complete cleaning of the condenser and evaporator using a non-corrosive product.
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Drying of the drain area and disinfection to prevent mold growth.
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Re-wiring near the board, with insulating sleeves and reinforced fasteners.
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Test the built-in thermostat and recalibrate the temperature probe.
Once the repair was complete, we powered up the system and ran a full air conditioning cycle . The compressor started normally, the blown air temperature dropped to 13°C , and the customer immediately noticed optimal comfort returned.
Results and recommendations
Thanks to our intervention, the Friedrich PTAC air conditioner has regained its original efficiency. The unit now operates quietly, with optimal energy efficiency and regular heat release .
Our technicians also took the time to explain some good maintenance practices to the customer:
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Clean filters every 4 to 6 weeks , especially during the summer.
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Visually check that nothing is obstructing the outdoor coils .
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Schedule annual preventative maintenance including compressor and control board testing.
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Avoid blocking the lower ventilation grille to allow good air circulation.
These simple actions extend the life of the device and reduce the risk of overheating or breakdown during periods of high demand.
AirGreen expertise at your service
PTAC units are often overlooked when it comes to maintenance because they are discreet and integrated into the wall. Yet, they require just as much care as a wall-mounted heat pump or central system .
At AirGreen , we service all brands of PTAC and VTAC, including Friedrich , Gree , Comfortmaker , and Midea . Our technicians have the specialized tools to diagnose and repair these systems quickly, while respecting electrical safety and energy efficiency standards.
We serve Montreal, Laval, Longueuil , as well as the entire North Shore and South Shore , with rapid and guaranteed interventions .
Conclusion: comfort restored, confidence assured
This repair in Outremont perfectly illustrates the AirGreen philosophy: to intervene with rigor, transparency, and efficiency. Every detail counts—from diagnosis to restoration—to ensure the lasting comfort of our customers.
The owner, satisfied with our intervention, also decided to subscribe to our annual AirGreen maintenance program , guaranteeing the proper functioning of his PTAC throughout the year.